He lost all self control. He was forced to act against his will. He has survivor’s guilt (despite not killing anyone) ontop of it. And even if he didn’t kill anyone, it makes sense for him to have that guilt because he did attack people. He may lament that “he enjoyed it as it happened” or it may be just another figment of his guilt manifested because. Jesus. What happened to him is horrible.
It makes sense that Anduin is messed up over it. Hating him for being messed up for it is dumb.
What isn’t dumb is pointing out that Anduin is shielded from any wrong doing by the development staff. He is their perfect angel. Their baby boy. He can NEVER be morally wrong. At all. Ever. So, you’re correct to draw the distinction that – while it’s correct that Anduin would be emotionally scarred by the event – we the players know he didn’t do anything that was scarring. So, we emotionally don’t care that he feels that way.
Compare and contrast Anduin with Garrosh and how their crimes are portrayed and carried out. Or Sylvanas. Or Overlord Kromgarr. Or Grom. Or Guldan.
The distinction between the two might be hard for the layman to consider if they haven’t spent a lot of time thinking about the story both as it is written and how it is written. So, I understand why people are pointing out that Anduin is just sad. But aim your frustration at Blizzard, not the character.
It’s a better way to get your point across.